There will basically certainly be AI stuff in 18.4. Apple just told us a couple days ago they would drop new Apple Intelligence features in early April. If they were having such issues with these features that they decided they would have to remove them and postpone them to 18.5, it would make absolutely no sense to promise them in early April. Now it is up for question what Apple Intelligence features Apple will release in April (it’s possible the Siri enhancements won’t be part of that), but there’s basically zero question that 18.4 will add Apple Intelligence features because Apple just told us as much two days ago. Personally, I think there’s a good chance we’d possibly see at least some of the Siri enhancements in 18.4. I don’t think Apple has to deliver all of them at once, they’ve actually already shown they can slowly improve Siri with the ChatGPT integration. They didn’t try to roll out all of the enhancements at once when they added that, I see no reason they couldn’t possibly improve the conversational abilities of Siri without the on-screen awareness or vice versa, they aren’t really inter-reliant features. But we’ll see, perhaps Siri enhancements won’t come in 18.4. The thing that is virtually certain though is that 18.4 will indeed add AI features, and beyond that will also likely add smaller OS features like new Default Apps categories, unlike 18.3 which added nothing.